differential_equations/methods/irk/fixed/
mod.rs

1//! Implicit Runge-Kutta solvers with Newton iteration.
2
3mod ordinary;
4//mod delay;
5
6use super::ImplicitRungeKutta;
7use crate::methods::{Fixed, Ordinary};
8
9use crate::{
10    traits::{CallBackData, Real, State},
11    tableau::ButcherTableau,
12};
13
14// Macro for fixed step constructors
15macro_rules! impl_irk_fixed_step_constructor {
16    ($method_name:ident, $order_val:expr, $s_val:expr, $m_val:expr, $doc:expr) => {
17        impl<E, T: Real, V: State<T>, D: CallBackData> ImplicitRungeKutta<E, Fixed, T, V, D, $order_val, $s_val, $m_val> {
18            #[doc = $doc]
19            pub fn $method_name(h0: T) -> Self {
20                let tableau = ButcherTableau::<T, $s_val>::$method_name();
21                let c = tableau.c;
22                let a = tableau.a;
23                let b = tableau.b;
24                
25                ImplicitRungeKutta {
26                    h0,
27                    c,
28                    a,
29                    b,
30                    order: $order_val,
31                    stages: $s_val,
32                    dense_stages: $m_val,
33                    ..Default::default()
34                }
35            }
36        }
37    };
38}
39
40// Fixed step methods (embedded error estimation, Newton iteration)
41impl_irk_fixed_step_constructor!(backward_euler, 1, 1, 1, "Backward Euler method of order 1 with 1 stage. A-stable and suitable for stiff problems.");
42impl_irk_fixed_step_constructor!(crank_nicolson, 2, 2, 2, "Crank-Nicolson method of order 2 with 2 stages. A-stable and suitable for stiff problems.");
43impl_irk_fixed_step_constructor!(trapezoidal, 2, 2, 2, "Trapezoidal method of order 2 with 2 stages. A-stable and suitable for stiff problems.");
44impl_irk_fixed_step_constructor!(radau_iia_3, 3, 2, 2, "Radau IIA method of order 3 with 2 stages. A-stable and suitable for stiff problems.");
45impl_irk_fixed_step_constructor!(radau_iia_5, 5, 3, 3, "Radau IIA method of order 5 with 3 stages. A-stable and suitable for stiff problems.");
differential_equations/methods/irk/fixed/mod.rs

differential_equations/methods/irk/fixed/
mod.rs
